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ObjectiveThe aim of this study was to establish a method for determining inorganic， methyl， and ethyl mercury levels in fish using L-cysteine-assisted extraction-high-performance liquid chromatography-inductively coupled plasma mass spectrometry.MethodsL-cysteine was used to extract mercury from the samples. The extraction efficiencies of different concentrations of L-cysteine were investigated. The effect of extraction time on extraction efficiency was also studied， and the mobile phase conditions were optimized.ResultsUsing a mobile phase comprising 2% methanol + 0.04 mol/L ammonium acetate + 1 g/L L-cysteine， the three forms of mercury in fish were determined by ultrasonic-assisted extraction with 1% L-cysteine for 10 min. All samples were separated within 9 min. The linear correlation coefficients for the three forms of mercury were over 0.999. The limits of detection of inorganic mercury， methyl mercury， and ethyl mercury were 3.0， 2.0， and 3.0 μg/kg， respectively. The spiked recoveries were 92.2%-97.9%， and the precision was less than 2%. The measured values of the quality control samples were within the range of the fixed values.ConclusionThe method developed herein is accurate， simple， convenient， and suitable for determining the three types of mercury in fish.

The plant-specific IDD transcription factors (TFs) are vital for regulating plant growth and developmental processes. However, the characteristics and biological roles of the IDD gene family in tomato (Solanum lycopersicum) are still largely unexplored. In this study, 17 SlIDD genes were identified in the tomato genome and classified into seven subgroups according to the evolutionary relationships of IDD proteins. Analysis of exon–intron structures and conserved motifs reflected the evolutionary conservation of SlIDDs in tomato. Collinearity analysis revealed that segmental duplication promoted the expansion of the SlIDD family. Ka/Ks analysis indicated that SlIDD gene orthologs experienced predominantly purifying selection throughout evolution. The analysis of cis-acting elements revealed that the promoters of SlIDD genes contain numerous elements associated with light, plant hormones, and abiotic stresses. The RNA-seq data and qRT-PCR experimental results showed that the SlIDD genes exhibited tissue-specific expression. Additionally, Group A members from Arabidopsis thaliana and rice are known to play a role in regulating plant shoot gravitropism. QRT-PCR analysis confirmed that the expression level of SlIDD15 in Group A was high in the hypocotyls and stems. Subcellular localization demonstrated that the SlIDD15 protein was localized in the nucleus. Surprisingly, the loss-of-function of SlIDD15 by CRISPR/Cas9 gene editing technology did not display obvious gravitropic response defects, implying the existence of functional redundant factors within SlIDD15. Taken together, this study offers foundational insights into the tomato IDD gene family and serves as a valuable guide for exploring their molecular mechanisms in greater detail. [ABSTRACT FROM AUTHOR]

Semi‐leafless represents an advantageous plant architecture in pea breeding due to its ability to enhance resistance to lodging and potentially to powdery mildew. The introduction of semi‐leafless pea varieties is considered a seminal advancement in pea breeding over the past half‐century. The afila (af) mutation leads to the replacement of lateral leaflets by highly branched tendrils; combined with the semi‐dwarfing le mutation, it forms the semi‐leafless cultivated variety. In this study, we identified that mutations in two tandemly‐arrayed genes encoding Cys(2)His(2) zinc finger transcription factors, PsPALM1a and PsPALM1b, were closely associated with the afila phenotype. These two genes may be deleted in the af mutant. In situ hybridization showed that both genes exhibit specific expression in early leaflet primordia. Furthermore, suppression of PsPALM1a/PsPALM1b resulted in a high frequency of conversion of lateral leaflets into tendrils. In conclusion, our study provides genetic evidence demonstrating that mutations in PsPALM1a and PsPALM1b are responsible for the af locus, contributing to a better understanding of compound leaf formation in peas and offering new insights for breeding applications related to afila. [ABSTRACT FROM AUTHOR]